Data mining, also known as knowledge discovery in databases (KDD) has been defined as the nontrivial extraction of implicit, previously unknown, and potentially useful information from data. Many known techniques such as machine or statistical learning, are used to discover and present knowledge from databases in a form easily comprehensible to humans.
Machine learning usually refers to a change in a system that performs artificial intelligence based tasks, in response to input values. These input values are sometimes referred to as the observed variables or the training set. For example, after a speech recognition system has heard a number of voice samples, the system improves its speech recognition capability using a machine learning algorithm. This technique also has applications in other areas such as classifying DNA sequences, stock market analysis, predictions, and robotic controls. For example, a stock market analysis system may base on the historical stock performance in predicting future stock performance. The analysis system learns the historical stock performance and improves its ability to make more accurate predictions.
Microelectronic manufacturing companies have utilized machine learning to analyze the dynamic characteristics of manufacturing process related data sets. Such characteristics include final electrical performance binning, temperature variation during the process, chemicals usage, wafer sorting, clocking speed, and power consumption of the final packaged microelectronic devices.
Integrated circuits are typically manufactured on a wafer of silicon. Each wafer may contain several hundred integrated circuits (IC). The wafer is then divided into separate die or chips each containing an integrated circuit (IC). This process is also known as wafer saw. A die is a microelectronic device which has not yet been packaged.
There is an ever increasing demand for fast microelectronic devices that are capable of multitasking. Multi-chip package (MCP) technology provides a solution to achieve better multitasking by packaging more than one microelectronic die on a substrate. Subsequent to the wafer-saw, a Tape Reel Die System (TRDS) may be used to pick die from the wafer and place them on a tape reel in a sequence. The microelectronic die are then packaged, typically in the order in which they were received on the tape reel. Conventionally, the sequence in which a microelectronic die is picked from the wafer is hard coded in the TRDS and once the sequence is programmed in TRDS, it is not adjustable.
There may be hundreds of die in the same wafer and accordingly there are different ways of selecting the sets of die to be packaged on one substrate. One possibility is a simple, serpentine sequence in which adjacent die may be picked and packaged together, moving back and forth in rows. For example, the TRDS pick-and-place arm may start at the upper left die, travels across the row, and wraps back towards the left at the subsequent row. Another possibility is a spiral sequence in which adjacent die may be picked and packaged together, in a circular sequence staring from an outer most row, traveling down an outer column, across another outer row then up another outer column, and continuing inwards.
The particular microelectronic die should be packaged together depend greatly on the quality of each die. Conventionally, die with similar qualities are packaged together. The quality of each microelectronic die depends on its manufacturing process and the processing environment. A manufacturing process has temperature variations and uneven chemical distributions which result in defective microelectronic devices, or devices having different characteristics and qualities. Die with difference qualities should not be packaged in the same MCP. For example, if the clocking of each die in a MCP does not match with other die packaged on the same MCP, the performance and the sales distribution of that packaged unit may be limited by the die with the lowest clock speed. Consequently, this MCP may result in lower performance and lower profit yield.